new parser for movie header box

Box.go

@@ -26,6 +26,8 @@ const (
 	BoxTypeMediaData = "mdat"
 	// BoxTypeMovie Movie Box
 	BoxTypeMovie = "moov"
+	// BoxTypeMovieHeader Movie Header Box
+	BoxTypeMovieHeader = "mvhd"
 	// BoxTypeMovieFragment Movie Fragment Box
 	BoxTypeMovieFragment = "moof"
 	// BoxTypeMovieFragmentHeader Movie Fragment Header Box

MovieHeaderBox.go

@@ -0,0 +1,110 @@
+// Copyright 2024 Martin Riedl
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package gomp4
+
+import (
+	"encoding/binary"
+)
+
+// MovieHeaderBox Movie Header Box struct
+//
+// 8.2.2 Movie Header Box
+// Box Type: ‘mvhd’
+// Container: Movie Box (‘moov’)
+// Mandatory: Yes
+// Quantity: Exactly one
+//
+// This box defines overall information which is media‐independent, and relevant to the entire
+// presentation	considered as a whole.
+type MovieHeaderBox struct {
+	*FullBox
+	// is an integer that declares the creation time of the presentation (in seconds
+	// since midnight, Jan. 1, 1904, in UTC time)
+	CreationTimeV0 uint32
+	// is an integer that declares the creation time of the presentation (in seconds
+	// since midnight, Jan. 1, 1904, in UTC time)
+	CreationTimeV1 uint64
+	// is an integer that declares the most recent time the presentation was
+	// modified (in seconds since midnight, Jan. 1, 1904, in UTC time)
+	ModificationTimeV0 uint32
+	// is an integer that declares the most recent time the presentation was
+	// modified (in seconds since midnight, Jan. 1, 1904, in UTC time)
+	ModificationTimeV1 uint64
+	// is an integer that specifies the time‐scale for the entire presentation; this is the
+	// number of time units that pass in one second. For example, a time coordinate system that
+	// measures time in sixtieths of a second has a time scale of 60.
+	Timescale uint32
+	// is an integer that declares length of the presentation (in the indicated timescale). This
+	// property is derived from the presentation’s tracks: the value of this field corresponds to the
+	// duration of the longest track in the presentation. If the duration cannot be determined then
+	// duration is set to all 1s.
+	DurationV0 uint32
+	// is an integer that declares length of the presentation (in the indicated timescale). This
+	// property is derived from the presentation’s tracks: the value of this field corresponds to the
+	// duration of the longest track in the presentation. If the duration cannot be determined then
+	// duration is set to all 1s.
+	DurationV1 uint64
+	// is a fixed point 16.16 number that indicates the preferred rate to play the presentation; 1.0
+	// (0x00010000) is normal forward playback
+	Rate int32
+	// is a fixed point 8.8 number that indicates the preferred playback volume. 1.0 (0x0100) is
+	// full volume.
+	Volume int16
+	// provides a transformation matrix for the video; (u,v,w) are restricted here to (0,0,1), hex
+	// values (0,0,0x40000000).
+	Matrix []int32
+	// is a non‐zero integer that indicates a value to use for the track ID of the next track
+	// to be added to this presentation. Zero is not a valid track ID value. The value of
+	// next_track_ID shall be larger than the largest track‐ID in use. If this value is equal to all 1s
+	// (32‐bit maxint), and a new media track is to be added, then a search must be made in the file for
+	// an unused track identifier.
+	NextTrackID uint32
+}
+
+// ParseMovieHeaderBox creates a new Movie Header Box struct
+func ParseMovieHeaderBox(filePosition uint64, headerSize uint32, content []byte) *MovieHeaderBox {
+	box := &MovieHeaderBox{
+		FullBox: newFullBox(&Box{filePosition, headerSize}, content[0:4]),
+	}
+
+	position := 4
+	if box.Version == 1 {
+		box.CreationTimeV1 = binary.BigEndian.Uint64(content[4:12])
+		box.ModificationTimeV1 = binary.BigEndian.Uint64(content[12:20])
+		box.Timescale = binary.BigEndian.Uint32(content[20:24])
+		box.DurationV1 = binary.BigEndian.Uint64(content[24:32])
+		position += 28
+	} else { // version == 0
+		box.CreationTimeV0 = binary.BigEndian.Uint32(content[4:8])
+		box.ModificationTimeV0 = binary.BigEndian.Uint32(content[8:12])
+		box.Timescale = binary.BigEndian.Uint32(content[12:16])
+		box.DurationV0 = binary.BigEndian.Uint32(content[16:20])
+		position += 16
+	}
+
+	box.Rate = int32(binary.BigEndian.Uint32(content[position : position+4]))
+	box.Volume = int16(binary.BigEndian.Uint16(content[position+4 : position+6]))
+	position += 4 + 2 + 2 + 8 // 4 bytes for rate, 2 bytes for volume, 2 bytes reserved and 8 bytes reserved
+	for i := 0; i < 9; i++ {
+		box.Matrix = append(box.Matrix, int32(binary.BigEndian.Uint32(content[position:position+4])))
+		position += 4
+	}
+
+	// skip 6*32 bit "pre-defined"
+	position += 6 * 4
+	box.NextTrackID = binary.BigEndian.Uint32(content[position : position+4])
+
+	return box
+}

Parser.go

@@ -110,6 +110,8 @@ func parseNextBox(reader io.Reader, filePosition uint64) (box interface{}, endPo
 		box = ParseMediaDataBox(filePosition, boxHeaderSize, boxContentBytes)
 	case BoxTypeMovie:
 		box, err = ParseMovieBox(filePosition, boxHeaderSize, boxContentBytes)
+	case BoxTypeMovieHeader:
+		box = ParseMovieHeaderBox(filePosition, boxHeaderSize, boxContentBytes)
 	case BoxTypeMovieFragment:
 		box, err = ParseMovieFragmentBox(filePosition, boxHeaderSize, boxContentBytes)
 	case BoxTypeMovieFragmentHeader:

README.md

@@ -22,7 +22,7 @@ Implementation progress
 | 8.1.2 Free Space Box                               | free, skip     |      - |
 | 8.1.3 Progressive Download Information Box         | pdin           |      - |
 | 8.2.1 Movie Box                                    | moov           |   100% |
-| 8.2.2 Movie Header Box                             | mvhd           |      - |
+| 8.2.2 Movie Header Box                             | mvhd           |   100% |
 | 8.3.1 Track Box                                    | trak           |      - |
 | 8.3.2 Track Header Box                             | tkhd           |      - |
 | 8.3.3 Track Reference Box                          | tref           |      - |